PROJECT SUMMARY (See instructions); While musculoskeletal tissues have several biological roles, by far their primary function is to provide mechanical load support and motion to the body in response to the activities of daily living. These load and deformation requirements vary with tissue type and location, but include significant mechanical demands such as high stiffness and strength, anisotropy (direction dependence), nonlinearity (increased stiffness as deformation increases), and viscoelasticity (time dependence and energy dissipation). With injury, aging, degeneration, or disease, musculoskeletal tissues may experience a decline in mechanical function. With development, growth, and therapeutic treatment, the mechanical function can improve. In short, assessment of musculoskeletal tissue mechanics should often be primary criteria in both basic and translational studies of degradation and treatment. Moreover, the innovation and sophistication of biomechanical quantification must continue at a pace on par with the ever-deepening knowledge of musculoskeletal tissue molecular biology, with advances in molecular and imaging technologies, and with new therapeutic developments in order to discern the functional outcomes in these studies. The overall objective of this Biomechanics Core (BC) is to develop and utilize a wide range of biomechanical approaches to evaluate musculoskeletal tissue damage and repair, and to provide training and funding for new projects and collaborations utilizing these assays. The Specific Aims are: Aim 1: To provide guidance and training on the capabilities, advantages, and disadvantages of the various methodologies to assess musculoskeletal tissue biomechanical function through formal educational enrichment programs and one-on-one interactions. Aim 2: To provide expertise and service for biomechanical assays of musculoskeletal tissues. Aim 3: To develop new biomechanical testing techniques that will be applicable to musculoskeletal research. Aim 4: To provide funding for development of new projects and collaborations and to develop preliminary and/or feasibility data for investigators.